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Alpha 1 impeller removal

J

johnb

Member
"I'm having trouble removi

"I'm having trouble removing the water pump impeller from the drive shaft. I sprayed with wd40 and tried to pry the impeller off. Any suggestions short of getting a gear puller to do the job?

Thanks,
John"
 
hi jhon i am 2 new at this inb

hi jhon i am 2 new at this inboard stuff. i just replaced mine last week and had the same problem. i just took a razor knife and cut mine off it was rubber and cut with ease. came right off.
 
"Just be careful not to damage

"Just be careful not to damage any plastic components about the pump area. Usually firm but gentle prying will cause it to lift free. Probably corrosion has bonded the key to the impeller preventing the impeller from lifting from the grooved the key rests in. It has simply wedged itself in place.

If you can spot the key, try tapping it free (downwards) from the impeller with a small screwdriver/hammer. The wd40 should have helped by this time. Then again try to lift the impeller up the shaft. You might try a few gentle taps on the center shell of the impeller to make sure it is also free of bonding with the shaft."
 
You may need to cut it off too

You may need to cut it off too. The first time I did mine it was on there such that I removed the rubber with a knife then the brass sleeve with a Dremel. Be very careful if you go that route...

Mike
 
"Thanks for all of the suggest

"Thanks for all of the suggestions. It would not pry off so I went the Dremel route (before I read Mike's post). That did the trick.

It may be of interest what I found after I removed the impeller:

The top half of the key pin was pretty mangled but did not interfere with the installation of the new impeller.

When I tried sliding the new impeller over the drive shaft, it stopped at a point just above the key slot. I ran my finger over the area and found a little burr on the shaft which I sanded smooth with the Dremel (120 grit sanding wheel). The impeller slid right on!

I also replaced the entire pump assembly. I figured why not, being that I had the whole thing apart anyway. All that's left is to put the drive back together and give it a test.

Thanks to everyone for all of their help.

John"
 
"We have a Mercruiser 5.0 Alph

"We have a Mercruiser 5.0 Alpha 1 that will not pump water from the drive unit to the top motor, we can send water down the tube from the top though, so we know that it is not blocked by a dirt dobbers nest, grass, or corn. We think that the impeller is either put in backwards or has a broken part. How do you open the drive unit? Do you need special tools? Is there somewhere online that we can see pictures of what the unit should look like?"
 
"[b]"Is there somewhere on

""Is there somewhere online that we can see pictures of what the unit should look like?"

Ayuh,....

Find My thread titled "Auyh,.. The Backdoor is Open again", or something like that,....
Then follow the links to the Factory Manuals for Your motor,+ drive...."
 
"All I can say from his experi

"All I can say from his experience is why the h*ll don't people read the readily available instructions before thinking they know it all, and starting a job they are not prepared for??

He could have saved himself a lot of grief and cursing, and possible expensive damage. The brute force technique is never a good idea with boats.

And he found the hard way to install the new impeller. Its much easier to slide the impeller down the shaft with the key in place, then slide the upper pump housing over the impeller while rotating it Ccw. What could be easier than that?

Rod"
 
"LOL!

I noticed the same th

"LOL!

I noticed the same things...the really funny part is if you read his captions, he did too! He just couldn't be bothered to locate his service manual before he started the job.

I was still glad to find his gallery because even though I have an SM for my OD, I'd still never actually torn into it...and lots of live color photos are much better than a few pencil sketches in a manual.

Another thing I did differently was how I held the prop still to remove/retorque the nut. Not having a 2x4 handy, I looped my trusty strap wrench around the prop aft of the blades to hold it in place while I attacked the nut with my 3' torque wrench."
 
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